High frequency conductor system



March 14, 1939..l

J. w.,MlL |'\1oR` HIGH VFREQUENCY CONDUCTOR SYSTEM Filed oct.. 1e, 1956 4 Sheets-Sheet 1 March 14, 1939. l 4 1 lw MlLNoR 42,150,451.

HIGH FREQUENCY CONDUCTOR SYSTEM Filed ont. 1e, 195e 4 sneets-sheet'z l FIG. 2

b d o e c v 19g Z0- 2| Ib IC=.21 1 1d lean(J FIG. 3

f b d a e c y g T T T- A magg 20a Idle IbLIIc Ifg Id Ip I? FIG..4

b d a e c T T" T ,1T 1d=1e 1b=1c l l I l CURRENT uN ADJACENT b d l e C, WIRE-fs INVERTICAL AND HoRzoNTAL Rows T T T EQUAL AND OPPOSITE |N olREcTmN i 19 b` v INVENTo l J.w.M|| NoR 2o b BY March 14, 1939*. J. w. MlLNoR HIGH FREQUENCYCONDUCTOR SYSTEM Filed 06;'. 1e, 193e 4 sheets-sheet 5 FIG. 5

- d c b u u b." c' d' 6B v e9 Q e e CURRENT m u .AND q' EQUAL AND oPPosHE \N mREcTmN n C l n a. l. .l d H vd' .l u n' FIG. 6

March 14, 1939. v J. w. MILNoR 2,150,451

` HIGH FREQUENCY CONDUCTOR SYSTEM Filed Oct. 16, 19.36 4'SheetS-sheet 4 INVENTOR J.w.M|| NoIR ATTORNEY Patented'Mar. 14, 1939 UNITED STATE man rnEQUENc! coNDUc'roa SYSTEM PATENT oFFicE Jnseph w. minor, Maplewwa'N.' J., assignmto The Western Union Telegraph Company, New York, N. Y., a corporation of New York application october 1s. 1936, serial No. 106,036

20 Claims.

My invention relates to a high frequency" conductor system, and particlarly to a high frequency communication system cable to open wire conductors.

especially appli- Ordinarily, open wire communication lines,

even though carefully paired and transposed in the usual way, may not be used for the transmission of frequencies above theorder of 20,000 cycles, and to extend ,the range to include frequencies as high as 50,000 cycles or more requires the employment of special arrangements of the conductors. These special arrangementsmayrequire more frequent transpositions, special spacing of the conductors, special -low loss insulators, bonding of the insulator pins, soldering l of the wire joints, and in general necessitate a very high d egree of care in construction, resulting in undesirably high installation and maintenance costs. For higher frequency ranges, even these precautionsare inadequate to prevent inductive eifects and radiation of energy, thus causing losses andA also interference with other transmission systems or with radio receivers and,

in turn, causing the circuit to be highly suscept-v ible to'interference from external electric and magnetic fields.

One of the objects of the invention is provide a novel and improved high frequencysystem in which radiation losses and inductive effects of the system on other circuits are and which has low susceptibility to interference from external fields.

Another object ist. mutable systm for nigh frequency transmission applicable to ordinary ,'tors.

A n additional object is to increase the carrying capacity and provide new vuses for existing standard hues.

'I'he invention further resides system having the novel closed and claimed. 1

' open wire communication conductors without re- 'quirlng spaci'al rearrangements of the conducin a transmission features hereinafter dis- In -orderto describe the invention, and for illustration of some of the various forms it may take, reference'is had to the accompanying'drawings, in which: i

Fig. l is a schematic circuit diagramiof a composite telephone and telegraph 4system embodying -the invention:

r Fig. 2 illustrates the relative direction. of ilow and relative values of the high frequency currents flowing in adjacent ones of the five line wiresofthesystemofl'lml;

Fig. 3showstlieiriventltli apnea-'w seven;

transformers arranged to maintain the desired current relations between adjacent.- conduptors; 15

' and Fig. 9 shows a choke coil and transformer arrangement formaintaining the desired current relations between the conductors of the system.

Referring now to Fig. 1 of the drawings, there 20 is shown a composite telephone and telegraph system having two stations A and B interconnected by a line comprising five open wireconductors a, b, c, d, and e disposed substantially in the same plane, such as the-five adjacent wires -on across-arm of a telegraph route. At station A means are provided for transmitting and receiving voice frequencies, for exampl telephone messages, over a circuit Il) connectedto a pair of the conductors a to e, such as conductors c and e, the circuit continuing to station B where conductors I0" complete the circuit to a second voice frequency receiving and transmitting station.

-Choke coils l2 and I2' are inserted in the lines Ill and l0 at the respective s ions to prevent 35 the admission to the voice frequency transmitter and receiver of the high frequency currents inafter referred to. Direct current telegraph circuits I3` and Il atthe respective stations may also be connected, through suitable composite apparatusCx diagrammaticaily 'indicated at l5, l5', to- `the circuitsl l0 and lll'.;p -Various methods and types of apparatus for vthus compositing a ,circuit are well knowninthe art and for this reason are not here described 'in detail.- Other telephone 46.

and telegraph circuits may be connected,through. choke coils, to the other threev conductors a, b and d to form other paired or single conductor circuits, as is indicated by the terminating conductors connected thereto.

Stations A and B transmitting and receiving apparatus I1 and Il for `sup'erimposing any desired number of high frequency channels on the .line wires a to e, thefrequencies-ofwhich be 5.5s

alsocompse highfrequency i and frequently are of the order of 50,000 cycles or more. 'I'he high frequency connections may be extended to any of a number of well known types of t erminal or repeater apparatus Where the high frequency currents may be repeated directly into other line sections or may be converted into Asignals of another character by means of the proper modulating and demodulating apparatus for connection to terminal apparatus or for extension over ordinary lines to more distant points. The high frequency system may be used entirely for transmission in one direction or portions of the frequency range maybe allotted for transmission in opposite directions.

The high frequency currents are impressed on, and are received from, the conductors a to 'e preferably by means of coupling devices such as the transformers T and T each comprising primary and secondary windings i9 and 20. The Winding I9 of eachtransformer is connected to the high frequency apparatus, and the other winding 20 has one end 2l thereof connected through two of the blocking condensers 22 to the conductors d and c, and the other end 23 lof the winding 20 is connected through another of the blocking condensers 22 to the centrally disposed line conductor a. A tap taken from the winding 20 at the point 2li is connected through i `conductors, the direction of ow of the high frequency current at any instant being in opposite directions in adjacent conductors, the instantaneous values of the high frequency current flowing in the respective conductors at any instant being progressively less in magnitude from a centrally disposed conductor or conductors of the group towards the outer conductors -of the group. When the high frequency current values are properly adjusted as between the various conductors, the foregoing arrangement minimizes the radiation losses and inductive effects of the system on other circuits, and also causes the system to have low susceptibility to interference from external electric and magnetic elds. The relative high frequency current value s in the various conductors of the system may be determined empirically or may be computed from known engineering formulae for expressing the electromagnetic and electrostatic relationA between the conductors of a circuit, thercurrent values also being adjusted, if necessary, to compensate for the individual electrical characteristics of the circuit.

In the specific `arrangement disclosed in Fig. 2, the transformer connections are such that the high frequency current values are as follows:

The current flowing in conductor b isv approximately equal to lthe current in conductor c but is only 0.2 of the current in conductora, and the current in conductor d is equal to the-current in 4conductor e and is approximately 0.7 of the curv considerable limitsl depending upon the particular characteristics of the system, the purpose for which it is intended, and the desired degree of wire route. vflowing in the adjacent conductors in both verfreedom from interference. The relative current values in the respective conductors a to e may be modified or changed by varying the point or points at which the transformer winding 20 is tapped, or by the addition of impedance networks in circuit with the individual conductors, or in any other suitable manner. The transformer maybe provided with a number of taps extending from the Winding 20 and coacting with an advjustable arm or connector, whereby the relative current values in the conductors may readily be changed in service to meet temporary disturbing conditions. may be employed to maintain the desired relative current values in the conductors a to e. That the flow of current at any instant is in opposite directions in adjacent conductors is indi cated by the two different markings in the small circles which represent the conductors, the instantaneous flow of current being in one direction in the conductors marked with a cross and in the opposite direction in the conductors marked with a dot.

Where the open wire conductors must be carried through entrance cable or other sections of cable, a similar choice of conductors in the cable may be employed; that is, a number of conductors mayA serve for transmission in one .direction while an intermingling group of conductors may comprise the return circuit. If desired, Special cables ,of types suitable for the transmission of such frequencies may be installed. This system of conductors in which heavier currents are carried by a symmetrically surrounded series of conductors, the surrounding conductors carrying lower' currents, can'be installed in numbers on a single pole line with materially reduced interference overthat ordinarily encountered in two con- .ductor systems. At the same time the considerablenexpense of providing special transpositions and modifications that wouldotherwise be required is avoided.

Fig, 3 shows a systemv in which seven conductors in a plane are employed, the connections to the conductors being made by means of a suitably connected tapped transformer winding 20a generally in the manner hereinbefore set forth in regard to the li'lvel conductor system. In this figure the high frequency current in conductor d equals the current in conductor e; the current in conductor b equals the current in conductor c;

. and the current in conductor f equals the current in conductor g. The current in conductor ais greater in magnitude than the current in conductor d; the current in d is greater than the current in b; and the current in b is greater than the current in f. The current values in the conductors therefore progressively diminish from the centrally disposed conductor a towards the outer conductors f and y. 'Ihe flow of Icurrent at any instant is in opposite directions in' adjacent conductors, as will -be noted from the diierentmarkings in the small circles which represent the conductors. c, v

.In Fig. 4 the method of minimizing interference is extended to two similar groups of conductors located in parallel horizontal rows or planes, one above the other, such as thewires carried `by two adjacent cross-arms of 4an open- In this arrangement the' current tical and horizontal v-rows is equal and opposite in direction. In each horizontal row, due to the manner of connecting the taps from the trans- Also',vseparate transformer windingsv former winding 20h, the current in conductor 75 current vin conductor b is equal to the current in .conductor c. I'he current in a is greater than the current in d, and the current in d is greater than the current in b.

'In the conductor system' illustrated in Fig. 5,

Vthe system is built upon conductors in pairs, the high frequency current owing in the system being progressively less in magnitude from the centrally disposed or innermost pair ofthe group to the outermost pair. The currents are equal and opposite in direction in conductors a and a', b and b', c and c', and d and d', respectively.

The-manner in which the transformer connections may be made to give this arrangement will be apparent from a consideration of Figs. 3 and 4.

Figs. 6 and 7 are further illustrations of different forms of two dimensional symmetrical arrangements, of conductors. In these systems, due to the connections from the transformer windings\20c and 20d, the instantaneous current.

now is in] one direction in the central'conductor g and in'I one or more external groups of conductors g1, g, and is in the opposite direction in an intermediate group orgro'ups h, h1. lGroups.

of conductors, such as shown in these figures, particularly if individual groups be segregated from each other. as on the two sides of a pole, provide systems-which are free from interference troubles with all external elds to a relavv tively high degree. To simplify the drawings,

the bloclng condensers, such as condensers 22 of Figs. 1 to 4, are-not shown in Figs. 6 and 7,' although i t will be understood that such condensers ordinarily will be used.

Systems in accordance with the invention will,- of course, operate most satisfactorily if l the v conductors are identical and symmetricall disposed with respect to each other. 'Various irregularities, however, may be compensated by 'adjustments of the relative terminal voltages.`

While a number ofv conductors are employed for a single system which may accommodate a large number of channels, thus m'aking the system susceptible to a considerable failure hazard, it is possible by means of simple switching arrangements to reduce the number of conductors in the.

system by a proper number of wires in the case of failure 'of any wire so that the system can continue in operation' at 'somewhat reduced eiliciency. A

When high frequency currents are transmitted along conductors in accordance with the systems hereinbefore disclosed, they may undergo .non-

uniform attenuation due to nonuniformities in the nature of the conductors. spacing, etc.` In

case it is\desirable atlocations other than the terminal or repeater points to -secure a more vnearly perfect rneutralizationl of -the external fields, the current-proportions in the various conductors of the system may bereadjusted by various methods such, forexample. as shown in Figs. 8 and 9. In Fig. 8 themethod is applied to the ilve wire conductor system of Fig. 1 ,l and comprisesl a system4 of .interconnecting transformers ,T2 to 'I'6 having turn ratios so proportioned as to vtend to maintain the required current relations between the different conductors.V

vIn-rlig. -9 the high frequency circuit is eilfec-` tively terminated-or divided-.into line sections, by the insertion oi' high frequency choke coils 26l into the following linesection in the, correctrelaby the transformer and the tor or conductors which either relate to, or are situated in or near, or contain or constitute the central portion of a group of conductors; 'andI-where reference is made to the flow of high frequency current in or over a conductor or conductors, this includes the iiow -of such current either through such conductors, or on or along the surfaces thereof.

It will be' appreciated that the foregoing illustrative embodiments of the invention ,will suggest various other specifically different embodiments and arrangements. to those -skilled in the art without departing from the spirit -of the invention, and theinvention intended to be covered -hereby is therefore not limited except as indicated by the scope of the appended claims.

I claim: f:

1. In a transmission system in which'a group of adjacent conductors are-substantia1ly parallel to each other, with at least one of said conductors being disposed intermediate other conductors of the group, the method which comprises transmitting a. high frequency current over each of a plurality of said conductors, causing the ilow of said high' 'frequency current at any instant to be in opposite directions in adjacent conductors of the group, and causing the instantaneous values of said high frequency current flowig in said conductors at any instant to differ in l:amplitude from an intermediate conductor .of said groupv lhighA frequency current at any instant to be in` opposite directions in adjacent conductors ofthe group, and causing the instantaneous values of said high frequency current iiowing irf said con-7'1" ductors at any instant tol diiier in amplitude from a centrallydisposed conductor of said group towards the outer conductors of the group.

3. In a transmission system in. which a. group .of adjacent conductors parallel ach other, 'said i group comprising centrally disposed conductors,

the method which comprises transmitting a high frequency signalling current over' each of a plus -rality of said conductors, causing the flow of said signalling current at any .instant to be in the same directionjnalternate ones of the conducf tors and in the opposite directionl in the remainder of the conductors, and causing the in-y stantaneous values of said signalling' current flowing in said conductors at any instant to be progressively less im amplitude from the centrally disposed conductors ofsaid group towards the outer conductors of the group. A

4. In a transmission system in which a high frequency` channel transmits a signalling current.

over each of aplurality of adjacent-conductors substantially paralleling eachother and forming a group, said group comprising at least one centrally disposed conductor, the method which comprises maintaining the instantaneous direction of flow of said signalling current the saine in alternate conductors and yopposite to the direction of4 ow of said current in the remainder of the conductors, and maintaining the relative current values of said signalling current in said group of conductors so as to be progressively less in magnitude in accordance with the radial distance of said conductors from a centrally disposed conductor of said group.

5. In a transmission system in which a plurality of pairs of adjacent conductors parallel each other to form a group, said group comprising at least one centrally disposed pair of conductors, the method which comprises transmitting. a. high frequency signalling current over each of a plurality of said conductors, causing the instantaneous signalling current in the two f conductors of each of said pairs to be equal in magnitude and opposite in direction and to be progressively less in magnitude in said pairs of conductors from a centrally disposed pair of said group towards an outer pair thereof.

6. A high frequency transmission system com-fA prising a group of adjacent conductors substantially parallel to each other, at least one of said conductors being disposed intermediate other conductors of the group,vmeans for transmitting a high frequency current over each of a plurality of said conductors, means for causing the transmitting a high frequency signalling current over each of a plurality of said conductors, means for causing the fiow of said signalling current at any instant to be in the same direction in alternate ones of the conductors and-in the opposite direction in the remainder of the conductors, and means for causing the instantaneous values of said signalling current flowing in said conductors at any instant to be progressively less in amplitude from the centrally disposed conductors of said group towards the outer conductors of the group.

8. A high frequency transmission system comprising a group of adjacent conductors substantially parallel to each other, said group comprising at least one centrally disposed conductor, means for transmitting a high frequency signalling current over each of a plurality of said conductors, means for maintaining the instantaneous direction of flow of said signalling current the same in alternate conductors of the group and opposite to the direction of iiow of said current in the remainder of the conductors of the group, and means for maintaining the relative current values of said signalling current in said group of conductors so as to be progressively less in magnitude in accordance with the radial distance of said conductors from a centrally disposed con-` ductor of said group.

9. A high frequency transmission system comprising a group of adjacent conductors substantially parallel to each other, said group comprising at least one centrally disposed conductor, Vmeans for transmitting a high frequency current over each of a plurality of said conductors, means for maintaining the instantaneous direction oij flow of said current in opposite directions in each two adjacent ones of said conductors, and means for maintaining the relative values of said .current in said group of conductors so as to be progressively less in magnitude in each two adjacent ones of the conductors from a centrally disposed one of the conductors of the group towards the outer ones of the conductors.

10. A high frequency transmission system comprising a group of pairs of adjacent conductors substantially parallel to each other, said group comprising at least one centrally disposed pair of conductors, means for transmitting a`high frequency signalling current over each of a plurality of said conductors, means for causing the instantaneous signalling current in the two conductors of each of said pairs to be equal in magnitude and opposite in direction, and means for causing said current to be progressively less in magnitude in said pairs of conductors from a centrally disposed pair of the group towards an outer pair of the group.

l1. A high frequency transmission system comprising a group of adjacent conductors substanopposite in adjacent conductors of the group, and

means for maintaining the instantaneous value of said signalling current in any of said conductors less than that of the value of said current in any of the other of said conductors nearer the central portion of the group.

l2. A high frequency transmission system comprising a plurality of groups of adjacent conductors substantially-parallel to each other, each of said groups comprising at least one centrally disposed conductor, said groups being disposed in adjacent planes respectively, means for transmitting a high frequency current over said conductors, means for causing the ow of said high frequency current at any instant to be in opposite directions in adjacent conductors of each of the groups and in opposite directions in adja-I cent conductors in different planes, and means for causing the instantaneous values of the high frequency current flowing in the conductors of each of said groups at any instant to diifer in amplitude from a centrally disposed conductor of the group towards the outer conductors of the group.

13. A high frequency transmission system comprising at least one centrally disposed conductor and surrounding groups of conductors substantially parallel to each other, means for transmitting a high frequency current over said conducing at least one centrally disposedA conductor, a`

source of high frequency current, a. high frequency couplingdevice connected to said'source l' of high frequency current, saidcoupling device having different portions thereof connected in circuit with diierent ones of said conductors,

taneous values of said high frequency current flowing in said conductors any instant'to be progressively less in amplitude from a centrally disposed conductor of the group towards the outer conductors of the group.

15. A high frequency transmissionsystem comprising a group of adjacent conductors substantially parallel to -each other, said group comprising at least oney centrally disposed conductor, a source of high frequency current, a transformer having a primary winding connected to said source of high frequency current and a secondary .winding having different portions thereof connected in circuit with different. ones of ,said conductors, respectively, theinstantaneous polarities of said portions of the secondary winding being such that the flow of said high frequency current at any instant is in opposite directions in adjacent conductors of the group, said portions of the secondary winding diering in ampere turns in such ratios as to cause the instantaneous values of said highfrequency current flowing in said conductors at any instant to be progressively less in amplitude from a centrally disposed conductor of the' group towards the outer conductors of the group.

16. A high frequency transmission system comprising a group of adjacent conductors substantlally. parallel to each other, a source of high frequency current, at least one of said conductors being disposed intermediate other conductors of the group, a transformer having a primary-winding connected to said source of high 4frequency current and a secondary winding having the opposite ends thereof connected `to different ones of said conductors and an intermediate portion of the secondary winding connected to the remainder ofsaid conductors in such manner that the flow of said'high frequency current at any instant is in opposite directions -in adjacent conductors of the group and the instantaneous values ofsaid high frequency current nowing in said conductors at any instant are pro-- gressivelyv less in amplitude from an intermediate one of said conductors of the group towards other conductors Aof the group.

17. A high frequency transmission system comprising a group of adjacent conductors substantiallyiparallel to each other, saidgroup comprising at least one centrally disposed conductor, a source of high frequency current, a transformer having a primary winding connected to said source of high frequency current and a secondary winding having the'opposite ends thereof con'- nected to different ones of said conductors and an intermediate portion of the secondarywinding connected to the remainder of said conductors in such manner that the flow of said high frequency current at any instant is in Opposite directions in adjacent conductors of the group and the instantaneous values of said high frequency current flowing in said conductors at any instant are progressively less in amplitude from Y a centrally disposed one of said conductors of the group towards the outer conductors of the group.

l 18. A high' frequency transmission system com- /prising a group of adjacentconductors Substantially parallel to each other, at least one of said c onductors being disposed intermediate other conductors of the group, a source of. high frequency current, a transformer having a primary winding connected to said vsource of high frequency current and a secondary'windng having one end thereof connected to a centrally disposed conductor o-f the'group and the other end thereof connected to other conductors of the group, the remainder of said conductors being connected at intermediate points of said secondary Winding in such manner that the flow of said high frequency current at any instant is in opposite directions in adjacent conductors of the group and the instantaneous values of said high frequency current flowing. in -said`conductors at any instant are progressively less in `amplitude from an intermediate one o-f said conductors of the group towards other conductors of the group.

19. A composite transmission system comprising a group of adjacent conductors substantially parallel to each other, said group comprising at least one centrally disposed conductor, means connected to said conductors for transmitting a high frequency current over each of a plurality of said conductors, other means for simultaneously transmitting a low frequency current over 'certain of said conductors, receiving means connected to said conductors responsive to said high frequency current, other means connected to said certain of the conductors for receiving said low frequency current, means associated with said high frequency transmitting means for'causlng the ow of said high frequencycurrent at any instant to be in opposite directions in adjacent conductors of the group, and means for causing the instantaneous values of said high frequency current owing in said conductors at any instant to be progressively less in amplitude from a centrally disposed conductor of said group towards the outer conductors of the group.

20. A high frequency transmission system comprising a group of adjacent conductors substantlally parallel to each other, said group comprising at least one centrally disposed conductor,

for transmitting a high frequency current over each o i a plurality of said conductors, receiving lmeans connected to said 'conductors responsive outer conductors of the group, and means vdisposed intermediate said transmitting and receiving means for readjusting the said relativelyinstantaneous values ofthe high frequency current flowing in the respectiveconductors.

VJOSEPH w. Manon.

50 transmitting means connected to said conductors 

